code: def toRNNBackend(
      inputRNN, num_layers, bidirectional=False, dropout=0
  ):
      """
      :class:`toRNNBackend`
      """
  
      deprecated_warning(
          "`apex.RNN` is deprecated and will be removed by the end of February 2023."
      )
      if bidirectional:
          return bidirectionalRNN(inputRNN, num_layers, dropout=dropout)
      else:
          return stackedRNN(inputRNN, num_layers, dropout=dropout)
  
file_path: apex/apex/RNN/models.py
imports: import torch
  from torch.nn._functions.rnn import LSTMCell, RNNReLUCell, RNNTanhCell, GRUCell
  from apex import deprecated_warning
  from .RNNBackend import bidirectionalRNN, stackedRNN, RNNCell
  from .cells import mLSTMRNNCell, mLSTMCell
label_desc: Use image node_id 1 for calling a global function with example usage: toRNNBackend(inputRNN, num_layers, bidirectional, dropout) and returns: bidirectionalRNN, stackedRNN